Saturday 30 March 2013

Daily League Sudoku #10: Average Sudoku

Another week, another Sudoku. This week an Average Sudoku. I like the idea. It's similar to Arrow Sudoku, except the digit is the average instead of the sum of the digits. I think enough can be done with it. I'm not sure if this idea has been done before, but I can't imagine it hasn't been. But I have that idea with any Sudoku Variant I come up with as there are already so many out there. But people constantly come up with new variants.
This Sudoku shouldn't be too hard. It has, like most my variants, a pretty narrow opening. But I think it should be clear where it lies this time. If you understand the basics of this variant it should go pretty smoothly. There's no real difficult steps in this puzzle, but you just have to go through them in the right order. I'm hoping this will have a bit faster times than my previous ones though. But I'm never sure how they'll turn out.

A recap of the last week's Daily Sudokus: Sunday's Outside Sudoku by Seungjae Kwak, Monday's Sum or Product Frame Sudoku by Min Young Yoo, Tuesday's Consecutive Sudoku by Prasanna Seshadri, Wednesday's Irregular Sudoku by Bastien Vial-Jaime, Thursday's Palindrome Sudoku by Rishi Puri, Friday's Tens Sudoku by Tom Collyer.

Daily League PDF file:
Week 10

Rules for Sudoku

In this Sudoku a digit in a circle is the average of the digits in all cells connected to it with a line.

Click to enlarge

Saturday 23 March 2013

Daily League Sudoku #9: Kid Sudoku

This week's Sudoku is a Kid Sudoku. When I first saw the idea, I just thought it was a funny idea. I don't remember where I first saw it though. I tried googling for other examples, but that proved to be unsuccesful. Apparently there are A LOT of websites with Sudokus for kids. I'm generally a fan of Sudokus with summed clues, so this was right up my alley for design. I wrote this puzzle in an hour long train ride back home. The opening was set up pretty quickly. I had an idea, it worked and as this type only clues in one direction, I knew I could always make the rest of the puzzle work. The center 99999 clue was something I wanted to keep in and in continuing the design it worked nicely with the clues. Finishing the puzzle took me a few tries so that there were no obvious new openings. I'm not sure how hard this puzzle is, but I suspect it to again be on the harder side. Hope everyone still enjoys it though.

A recap of the last Daily Week: Sunday's Rossini with Disjoint Groups Sudoku by Seungjae Kwak Monday's Irregular Sudoku by Fred Stalder, Tuesday's Weighted Killer by Prasanna Seshadri, Wednesday's Thermo Sudoku by Bastien Vial-Jaime, Thursday's Even/Odd Skayscraper Sudoku by Rishi Puri, Friday's Twodoku by Tom Collyer.

Pdf files of the last 2 weeks:
Week 8
Week 9

Rules for Sudoku

The clues on the outside are given by a kid that can't count past 9. He adds up all digits in each row from left to right. Every time the sum would go over 9 he restarts. So for example the clue for the row 154638279 would be 649899.

Click to enlarge

Thursday 21 March 2013

UK Puzzle Championship 2013

Today my puzzles for the UK puzzle championships. The UK Puzzle and Sudoku championships were held last weekend. Tom Collyer won the UK Sudoku championship and Neil Zussman won the UK Puzzle championship. My puzzles were the last individual round of the championship. It featured a relay, with 9 puzzles that have to be solved in order. Each puzzle solution would in some way transfer to the next, so that this puzzle would become solvable. I will be posting all puzzles and relay tags below, but to see how everything works, you can check the instruction booklet for this round here.

The original idea for this round came from the 2003 WPC in Arnhem. I have made a round like this before for another online competition. I used similar relays in that round as well. As that round wasn't done on time, I wasn't sure how many of these relays would work on time. Some relays are good without time, but things like copying the shapes of a Fillomino solution are very annoying in my mind for a speed contest.
The first puzzles I wrote were the Snake and Nurikabe puzzles, as I had used the Snake to Nurikabe relay before and liked it. I wrote a Snake puzzle with few clues, so that I could easily write a puzzle that had these clues inside the grid, which could then be transferred to the side. I then opted writing a Kakuro puzzle as the opening puzzle, as most solvers are familiar with that. With this the first 3 puzzles were all types that most people in the puzzling community have done multiple of. The next part of the design was getting from Nurikabe somehow back to number clues. I then found the combination Yin Yang/Hiroimono, which I thought was a nice transition, with a few less familiar puzzles. I did have to figure out how to properly write Hiroimono puzzles without any given clues as I had never done that before. From here I opted to write a Doppelblock puzzle. It was easiest to write this puzzle without any repeating clues as this would make the relay the smoothest. It was a bit hard to get it right, as some clues are just more conductive in this puzzle type. I was planning on writing a Minesweeper puzzle next, and figured I could easily relay it to any puzzle type. That's why I chose to write a Magnets next, which could transfer to a Battleships puzzle. I wrote a Magnets puzzle with missing clues, which I have written many of. I chose a smaller size as they are generally viewed as hard to many people. I had to make sure the remaining clues were under 20 as that's the max number of ship segments a standard Battleships puzzle has. It worked out perfectly and the Battleships construction was really easy to finish. When I went back, I couldn't get the Minesweeper in a way that the relay to it and from it was nice. That's why I tried a number of other puzzle types. Then I tried Country Road, which caused an odd design experience. I tried to write them normally, except I couldn't get it so it would transfer to the already written Magnets puzzle, so that's why I changed it around. I first marked a bunch of empty squares so that it would transfer properly to the Magnets puzzle, and then reversely engineered the regions so a solvable valid puzzle would exist which has those empty squares in those places. I think the result is nice and I doubt anyone would expect it was designed that way from the solve. I thought 9 puzzles would be enough, even though I had originally planned on making 10 puzzles. I just think some of the relays would take more time than others, so I thought this would make a long enough round for the championship.

The puzzles can be found below.

Tuesday 19 March 2013

Polish Puzzle Championships 2013

This week is a week full of puzzles on my blog. That is because the last two weekends there were two championships to which I contributed puzzles. Today I will post all puzzles from the Polish Puzzle Championship and Thursday will feature my puzzles for the UK Puzzle Championship.

The Polish Sudoku and Puzzle Championships were held in the weekend of 9 and 10 of March. Jan Mrozowski became the Polish Sudoku Champion. Przemysław Dębiak won the Polish Puzzle Championship. The puzzles for the Polish Sudoku Championship can be found here; the puzzles for thePolish Puzzle Championship can be found here. My puzzles were round 5 of the Puzzle championship. I also found a video of the Polish Puzzle Championship on Serkan Yurekli's blog. In the beginning you can see puzzlers working on my puzzle set. The end is the finals.

For the Polish Championship I employed a copycat theme. The puzzles came in pairs and each pair of puzzles had a similarity in the layout. Most of these types are very closely related in the puzzle type. The only pair that really isn't very close to the other were the Star Battle and Heyawake. I was happy to see that the puzzles were printed on bordering pages in the puzzle booklet, so solvers might notice the similarity.
The idea somewhat accidentally happened. I had made an easy Akari puzzle and wanted to make a harder regional Akari and opted to make one with the same black squares. When I finished those I wondered if I could keep doing that and went with a Liar Loop/Maxi Loop combo as that seemed most easily acchieved. And I'm pretty comfortable designing those, so made two with the same regions. The next puzzles I made were the Capsules and Ripple Effect puzzles, I posted earlier which ended up testing too hard. I really like constructing Ripple Effect puzzles, but clearly not that skilled at making them competition difficulty. I looked through my Double Trouble collection and thought Turning Fences and Slitherlink should be easily made look similar. I chose the same clue positions and about half the clues are the same. I already had 4 Loop puzzles, so that was all of those I could put in. I made a Tapa and Nurikabe with the same clue positions. I at first tried to also make the Nurikabe clues to be the sum of the Tapa clues, but that didn't prove to be very fruitful. I then started doodling a bit and made a Small Regions Star Battle and wondered what type I could use these cages for. I eventually settled on Heyawake as that would allow me to add some clues and see where it goes. The regions were still very restrictive on the Heyawake genre, but managed to push it out with just 2013 as clues. Lastly I needed some Magic Square genres. I thought first about doing Skyscraper/Haido, but figured with multiple similar types, maybe I should try a more different type. So I made a Skyscraper puzzle, to which I added a number of clues to turn it into an Easy as Japanese Sums puzzle. I felt I was somewhat missing a division type puzzle, but I couldn't find a nice way to make 2 that fit into the theme. And when I had the puzzles tested it seemed like there was enough to fill the hour slot already.

I also wrote a LITS puzzle to be used for the finals, except that one wasn't used. It willbe posted at the end of this post.

Puzzles can be found below.

Saturday 16 March 2013

Daily League Sudoku #8: Sum Sandwich Sudoku

Next week will be Richard Stolk's third LMI Sudoku test. The test is named V2V or Variations to Variations. It features 14 Sudoku puzzles, which consist of 7 Sudoku Variants and a variation of each. This week's Sudoku will be one of the V2V puzzle types.

I've chosen Sum Sandwich Sudoku as this week's puzzle type. I was debating between Rank Killer Sudoku and Sum Sandwich Sudoku, but I feel I generally design better Sudokus with outside clues. That's why I chose Sum Sandwich Sudoku. My first thought was to see if I could make one without any inside clues. But to set that up I was doing a lot of analysis of the interaction between clues, which I figure was making it a bit too hard. So I figured I'd probably better just make a more solvable Sudoku. So I set up the nice diagonal line of clues and started with the design. It still turned out a bit on the harder side, even though the all numbers are given did lead to a few unintended outside clues. But they don't ruin the opening, so I'm happy with the result. Enjoy.

It is now also possible to solve the Daily League puzzles on SudokuCup. The puzzles will appear there one day after they appear in the group and on the respective blogs.

A recap of the last week of the Daily League: Seungjae Kwak's Odd Sudoku, Fred Stalder's Diagonally Non-Consecutive Sudoku, Prasanna Seshadri's Galloping Horses Sudoku, Bastien Vial-Jaime's Figures Sudoku, Rishi Puri's Anti-Knight Sudoku and Tom Collyer's Diagonal Sudoku.

Rules for Sudoku

In this Sudoku for each row and column all digits are given that are sandwiched by two digits whose sum is equal to itself.

Click to enlarge

Saturday 9 March 2013

Daily League Sudoku #7: Ten Box Sudoku

I know there haven't been many puzzles from me lately, but my puzzle creating has been directed at other projects. A number of Puzzle Championships are coming up to which I contributed and I'm also working on contributing to Thomas Snyder's puzzle project. This all means there will be that eventually I will be posting a lot of puzzles after this is all over.

I'm still finding some time to make a Sudoku each week as that is a welcome break from making puzzles. For me in general designing a Sudoku just feels a bit different than designing any other puzzle. Although my puzzle mind still drives itself through in my Sudoku sometimes. This leads to me putting some more puzzly deductions in a Sudoku that I find very simple. For last week's Sudoku this was oriented around R5C5. I thought the deduction for that cell was pretty obvious, except I think that deduction got a lot of people very stuck and led to much slower times than I had expected.

This week I made a Ten Box Sudoku, which is a nice variation of the Toroidal Sudoku. I remember this variant from the WSC 2010. I liked that puzzle. It was also in the round I did best in. I still have a certificate from that round, showing that I was the best puzzler not in the top 10 in that round. It's not that hard a puzzle, but the variant has some tricks that really suit me so I'm reserving judgement on the actual times of the league's competitors.

In the last week we've seen the following Sudokus: Seungjae Kwak's Magic Summer Sudoku, Fred Stalder's Arrow Sudoku, Prasanna Seshadri's Search 9 Sudoku, Bastien Vial-Jaime's Renban Groups Sudoku, Rishi Puri's Even Odd Chessdoku, Tom Collyer's Number 8 Still Alive Sudoku.

Lastly, the PDF of week 7.

Rules for Sudoku

This Sudoku is made up of 10 rows, 10 columns and 10 3x3 boxes. Some of the boxes wrap around the edges of the grid.

Click to enlarge

Saturday 2 March 2013

Daily League Sudoku #6: Quad Second Sudoku

First off, yesterday the Puzzle Marathon on Logicmasters India started. It is a puzzle test which features 12 large puzzles by 12different authors. The contest will run from March 1st-March 10th. You can solve each puzzle seperately over the course of the week. This test features a Maxi Loop puzzle by me. Everyone should try to compete as there will definitely be some very nice puzzles. Even if you can only manage to solve a few of the puzzles, it should be worth the time.

Now back to this week's Daily League Sudoku. The last week has featured a nice Multiplication Table Sudoku by Seungjae Kwak, an easy Killer Pair Sudoku by Fred Stalder, a challenging but fun Point to the Next Sudoku by Prasanna Seshadri, a very hard Greater than Killer by Bastien Vial-Jaime, a Non-Consecutive Anti-Knight Sudoku by Rishi Puri and a Classic Sudoku by Tom Collyer.

This time I've made a Quad Second Sudoku, which is a twist on the Quad Max Sudoku. As far as I know it's an original variant. I think it changes the solve of a Quad Max enough to make for a fun new variant. For me personally this is my favourite puzzle I have made for the League so far. I think I got the right difficulty with this puzzle compared to some of my earlier puzzles. Hope enjoy it.

Lastly, here are the link to the PDF of Week 6.

Rules for Sudoku

In this Sudoku an arrow points at the second highest digit in the four cells around it. Digits may repeat around an arrow, but the second highest digit is always unique.

Click to enlarge